Button bleeder valve



July 27, 1965 K. A. BRANDENBERG ETAL 3,197,172

BUTTON BLEEDER VALVE Filed May 2, 1962 v JNVENTOR. KARL A. QRANDENBERG LOREN P. BART TEY United States Patent F was 3,197,172 BUTTUN ELEEDER VALVE Kari A. Brandenherg, an Leandra, and Loren R. hart, Hayward, Caliii, assignors to Modernair Corporation, San Leandro, Calih, a corporation of Ghio Filed May 2, W62, Ser. No. 191,)ti2 6 Claims. (1 25l23) recycling of a pneumatically operated control valve or the like in response to depression of the blceder valve button. More particularly, a pair of button bleeder valves are usually respectively connected to a pair of pilot chambers of the control valve which are normally pressurized from an air supply connected thereto. Upon depression of the button of one bleeder valve the pressure in the corresponding pilot chamber is exhausted through the bleeder valve such that the pressure in the other pilot chamber actuates the control valve in one direction. In a like manner depression of the other bleeder valve button effects actuation of the control valve in the opposite direction. Where conventional button bleeders are utilized for the foregoing purpose, it is necessary that the button of one be released prior to depression of the other. This precludes a number of possible control schemes which involve actuation of the control valve by depression of one button bleeder while the other button bleeder is held depressed.

Accordingly, it is an object of the present invention to provide a button bleeder valve of improved design which, when used in pairs to facilitate recycling of a pneumatically operated control valve or the like, permits actuation of the control valve with one button bleeder valve regardless of whether the other button bleeder valve is depressed or not.

Another object of the invention is the provision of a button bleeder valve of the class described whose internal control is based on pneumatic functions.

it is still another object of the invention to provide a button bleeder valve whose reclosing occurs when pressure in a bleed-elf line connected thereto has dropped to a predetermined minimum without regard to the position of the button.

Yet another object of the invention is to provide a button bleeder valve of the type described which may be employed in various novel pneumatic control systems entailing recycling of pneumatically actuated means in response to depression of one button bleeder while another button bleeder associated with the means is held depressed.

A further object of the invention is the provision of an improved button bleeder valve of the class described which is simple and economical in construction.

The invention possesses other objects and features of advantage, some of which, with the foregoing, will be set forth in the following description of the preferred form of the invention which is illustrated in the drawing accompanying and forming part of the specification. It is to be understood, however, that variations in the show ing made by the said drawing and description may be adopted within the scope of the invention as set forth in the claims.

FIGURE 1 is a diametric sectional view of a button bleeder valve according to the present invention, the valve being depicted in unactuated condition.

BJWJYZ Patented July 27, 1965 FIGURE 2 is a view similar to FIGURE 1, but with the button depressed and the valve undergoing a bleed-off phase.

FIGURE 3 is a view similar to FIGURES 1 and 2 illustrating the condition of the valve after the bleed-off phase is ended while the button is held depressed.

FIGURE 4 is a schematic diagram of one pneumatic control system which is facilitated by employment therein of button bleeder valves in accordance with the present invention.

Considering now the invention in some detail and referring to the illustrated form thereof in the drawing, there will be seen to be provided a button bleeder valve which is arranged to be internally pneumatically controlled. In broad terms the valve comprises body means in which a depressible actuating button is slidably disposed and spring loaded to a normally extended position. A plunger member is also mounted within the chamber in slidable relation to a recess within the button. The plunger is spring loaded to a normal position wherein a valve member carried by and movable with the plunger blocks communication between an inlet chamber and exhaust chamber which is ported to atmosphere. A valve seat is provided for the valve member. In addition the plunger and button define a sensing chamber therebetween which communicates with the inlet chamber through a passage formed in the plunger. Thus when the inlet chamher is connected to a compressed air source such as a pilot chamber of a pneumatically actuated valve, air from the source flows through the plunger passage into the sensing chamber to pressurize same. When the button is depressed, the force exerted thereon is transmitted through the air pressure in the sensing chamber to the plunger such that same moves with the button to a position opening communication between the inlet and exhaust chambers. Hence the pressure of the supply is bled from the inlet chamber to atmosphere through the exhaust chamber. Also the air in the sensing chamber is bled to atmosphere through the plunger passage and the inlet and exhaust chambers. As the pressure drops in the sensing chamber a reduced force is reached which is less than the loading spring force on the plunger. As a result the plunger moves within the depressed button to its normal position blocking communication between the inlet and exhaust chambers. Also the button and plunger are arranged to block communication between the plunger passage and sensing chamber and to port the latter to the exhaust chamber when such plunger movement occurs with the button in depressed position. Thus the bleed-off operation is terminated even though the button is depressed. When the button is released, the force of its loading spring returns the button to its normal extended position at t e same time opening communication between the plunger passage and sensing chamber and blocking communication between the latter and the exhaust chamber.

Considering now preferred structure for the bleeder valve outlined herein before, the body means is preferably provided as an elongated hollow cylindrical body 11 having radial ports 12 at a position intermediate its length. The body includes an internal constricted portion 13 between the ports 12 and one endv of the body. The con stricted portion partitions the body into the previously mentioned inlet chamber and exhaust chamber which are respectively designated as 14 and 15. Communication between chambers 14, 16 is provided through the central opening 17 in the constricted portion, and the periphery of the opening is bevelled on the inlet chamber side of the constriction to define a valve seat 13. The end or" the body corresponding to the inlet chamber (lower end of the body in the drawing) is advantageously provided with an internally threaded aperture 19 to facilitate connection of a pressure line in communication with the inlet chamber.

Slideably fitted within the opposite end of body 11 from inlet chamber 14- is the previously mentioned depressible button, which is designated by the numeral 21. Tie button recess is indicated at 22 and will be noted to include a cylindrical portion 23 extending into the internal end of the button, such portion outwardly tapering at 2 into a cylindrical portion as of slightly enlarged diameter. The enlarged diameter portion 26 is in turn inwardly stepped to a relatively small diameter portion 2'? and the juncture region between these portions is bevelled to define a valve seat 23.

The aforementioned plunger is designated by the numoral 29 and is preferably of elongated cylindrical form including an outwardly flared 31 at a position intermediate to length. The plunger is coaxially disposed within the body Ill and button recess 22. More particu larly, the plunger 31 is or" a comparable oiarnetcr to, and slideably disposed within the recess portion 2 3. The flange carries a concentric seal ring 32 which slideably engages the walls of recess portion 23 to effect a pressure tight seal therebetween. in ads on the'fiange is abutable with a retaining ring 33 secured within the end of button recess portion 23. When the abuts the retalning ring the seal ring 32 engage the wall of recess portion 23 immediately adjacent the outwardly tapered transition region 24. A seal ring 34 concentrically mounted adjacent the end of the plunger which projects into the button recess and which is sealingly engageable with seat 28 is at this time in disengaged position. 1 A chamber 35 defined by recess portion 2.7 hence communicates through the annulus between the plunger and seat 28 with a chamber 38 defined between the plunger flange 31 and base of recess portion 2s. Chamber 38 constitutes the sensing chamber of previous mention.

The section of the plunger on the opposite side of flange 31 is of sufiicient length to extend coaxially through the exhaust chamber 16 and the constriction aperture 17 into the inlet chamber 1 3. The end of such section carries a concentric seal ring or valve member 39 which is engageable with the seat 18 and when in engaged position blocks communication between the inlet and exhaust chambers 14 and 16. The plunger passage which provides communication between the inlet chamber sensing chamber then advantageously comprises a bore 41 extending coaxially through the plunger between its opposite ends. lreferably the bore is constricted to define an orifice 42 adjacent its terminal opening into chamber 36.

As regards the spring loading of the button 21 and plunger 29, coil springs 43, 44 are preferably coaxially mounted between the constricted portion 13 of body fl and the retaining ring 33 of the button, and between the constricted portion and the plunger flange Spring 44- thus acts to normally urge the plunger to a position wherein the seal ring 33 engages the seat 18. Spring 43 normally urges the button to an extended position relative to the body wherein the retaining ring 33 abuts the plunger flange 31.

Thus with the bleeder valve in its normal unactuated condition, the button and plunger are positioned relative to each other and to the body l1 as illustrated in FIGURE '1. With a pressure lirie communicably connected to inlet chamber 14-, air ilows through bore 41 into chamber 36,

and from this chamber into sensing chamber 38 as indi-' cated by the arrows in the figure. The sensing cham or is thus pressurized.

When the button 21 is depressed as illustrated in 1G- URE 2 to initiate a bleed-oil phase, the plunger 29 moves with the button by virtue of the pressure in the sensing chamber 38. As a result seal ring 39 is disengaged from seat 18 and air thus flows from inlet chamber 1% into exhaust chamber 16 and to atmosphere through ports 12. Air likewise tlows from the sensing chamber 38 and chamber 36 through bore ll to the inlet chamber, and therefore to atmosphere. The overall flow of air is as depicted by the arrows in the figure.

The pressure drops in the sensing chamber 33 spring 44.- is able to move the plunger in the direction of the base of the button recess 22. as depicted in 3. Seal ring 39 now engages seat 13 to block communication between the inlet and exhaust chambers thus terminating the bleed-oil phase. Seal ring 34 engages seat 28 to block communication between chamber 36 and sensing chamber Seal ring 32 is now moved beyond tapered region a position spaced radially inward from the walls recess portion 26. The sensing chamber is thus ported tween the plunger and recess walls to the exhaust chamber 16, and accordingly to atmosphere. Air pressure building up in the now closed inlet chamber is ac cordingly prevented from entering the sensing chamber until the depressing force on the button is removed.

By virtue of the automatic closure of the button bleeder valve of the present invention being eiiected in respo se to pneumatic pressure change without regard to the position of the button, the valve facilitates the use of various pneumatic control schemes heretofore impossible with conventional button bleeder valves. More particularly, multi-position pneumatically actuated control valves may for example be controlled by button blceders in accordance with the present invention with one bleed-er being operative to effect a shift of the control valve position even though the buttons of other blecder valves are retained in depressed position. One example of a system which utilizes this characteristic to good advantage is depicted in FEGURE 4. As shown therein, a conventional 4-way pneumatically actuated control valve 46 is connected in controlling relation to a double acting pneumatic cylinder 47. A pair of button blceders E3, 49 are 'espectiveiy connected to the pilot chambers of the control valve. When button bleeder 43 is depressed, the corresponding pilot chamber of the control valve is bled to atmosphere and the control valve established flow conditions to extend the piston rod 531 of cylinder 4 7. When button bleedcr 49 is depressed the other pilot chamber of the control valve bled to atmosphere and the flow conditions to the cylinder are reversed to retract piston 51.

A second double acting pneumatic cyli der 52 is similarly controlled by a 4-way control valve 53. In this instance, however, a button bleeder 54 in accordance with the present invention is connected to one pilot chamber of valve 53, and this blc-eclcr is disposed to be depressed by piston rod 51 in its extended position. The other pilot chamber of valve 53 is connected to button bleeder 49 When piston rod 51 is extended and bleeder 54 is thereby depressed the corresponding pilot chamber of valve 53 is bled to atmosphere to effect fiow conditions to the cylinder 52. productive of extension of its piston rod 56. Even though bleeder 54 is held depressed by piston rod 51, bleeder 49 may be depressed to return both piston rods 51 and 56 to their retracted positions.

What is claimed is:

1. A button bleeder valve comprising a hollow cylindrical body having an internal constricted portion intermediate the first and second ends thereof, said body having radial ports at a position intermediate the constricted portion and first end thereof, a button slidcably disposed within said first end of said body, said button having a recess in its internal end, said recess having a first portion connected by an outwardly tapered transition region to a second portion of enlarged diameter in turn connected to an inwardly stepped third portion of reduced diameter, means spring loading said button to a normal position extended from said first end of said body, a plunger coaxially disposed within said body, said plunger having an outwardly flared flange in slideable relation with said first portion of said recess, said plunger having a first end projecting from said flange into said third portion of said recess, said plunger having a second end projecting from said flange through said constricted portion, said plunger having a passage extending between its first and second ends, means spring loading said plunger in the direction of the first end of said body, retention means secured adjacent the outer end of said first portion of said recess and engageable with said flange, seal means carried by the second end of said plunger sealingly engageable with said constricted portion on the proximal side thereof relative to said second end of said body, second seal means carried by said flange sealingly engageable with said first portion of said recess, said second seal means engaging said first portion of said recess adjacent said tapered transition region when said flange engages said retention means, and third seal means carried by the first end of said plunger and sealingly engageable with the transition region between said second and third portions of said recess when said flange is disengaged from said retention means.

2. A button bleeder valve according to claim 1, further defined by said passage being a coaxial bore through said plunger having an orifice defining constriction adjacent the first end thereof.

3. A button bleeder valve according to claim 2, further defined by said means spring loading said button comprising a coil spring disposed between said constricted portion of said body and said retention means, and said means spring loading said plunger comprising a second coil spring disposed between said constricted portion of said body and said flange.

4. A button bleeder valve comprising body means defining an inlet chamber and an exhaust chamber communicated through a passage including a valve seat, a butt-on assembly including a first member mounted for reciprocation within a second member and defining therewith a sensing chamber within the second member, said first member movable within the second member between first and second positions wherein said first member is respectively relatively extended and retracted relative to said second member, means mounting said assembly within said body means for reciprocation as a unit between relatively extended and retracted positions, said first member having a portion engaging said valve seat in said first position when said assembly is in said extended position to block communication between the inlet and outlet chambers and disengaged from said valve seat when said first member is in said first position and said assembly is in said retracted position to establish communication between said inlet and exhaust chambers, said portion of said first member engaging said valve seat in said second position thereof when said assembly is in said retracted position, passage means extending between said inlet and sensing chambers including a passage in the first member, means for moving said first member between said first and second positions in response to a predetermined pressure decrease in said sensing chamber, and means blocking communication through said passage means when said assembly is in said retracted position and said first member i returned to said second position.

5. A button bleeder valve comprising a hollow body, a button slidably disposed within a first end of said body, said button having a recess in its inner end, means normally urging said button to an extended position from said first end, means defining inlet and exhaust chambers in said body communicating through a passage including a valve seat, said inlet chamber being adapted for connection to a pressurized air source, said exhaust chamber being ported to atmosphere, a plunger slidably disposed within the said button and defining a sensing chamber therewith, a valve member carried by said plunger and movable therewith, said plunger being movable between a first position wherein said valve member engages said valve seat to block communication between said inlet and said exhaust chambers and being movable to a second position disengaging said valve member from said valve seat to establish communication between the inlet and exhaust chambers, passage means extending between said inlet and said sensing chambers including a passage in the plunger, means normally urging said plunger in the direction of the outer end of said button to said first position, said sensing chamber being placed in communication with said exhaust chamber through said passage in the plunger when the button is initially depressed and the plunger is moved to said second position by movement of said button, means blocking said communication through said passage means when said button is held in its depressed position and said plunger is returned to its said first position, and means for returning said plunger to its first position when said sensing chamber and exhaust chamber are in communication.

6. A button bleeder valve comprising a hollow body, a button slidably disposed within a first end of said body, said button having a recess in its inner end, means normally urging said button to an extended position from said first end, means defining an inlet chamber in a second end of said body adapted for connection to a pressurized air source, means defining an exhaust chamber in said body intermediate said first and second ends and in coaxial communication with said inlet chamber through a passage including a valve seat, said exhaust chamber being ported to atmosphere, a plunger slidably disposed within said recess of said button and defining a sensing chamber therewith, said plunger projecting from said recess coaxially through said exhaust chamber and passage into said inlet chamber, passage means extending from said inlet chamber to said sensing chamber including a passage in said plunger, seal means carried by said plunger for engaging said seat and blocking communication between said inlet and exhaust chambers in a first position of movement of said plunger towards said button and disengaged from said seat and establishing communication between said inlet and exhaust chambers in a second position of movement of said plunger towards said inlet chamber, means normally urging said plunger to said first position, and means blocking communication through said passage means and establishing communication between said sensing and exhaust chambers when said button is depressed and said plunger is returned to said first position.

References Cited by the Examiner FOREIGN PATENTS 4,225 1883 Great Britain. 403,724 1934 Great Britain.

M. CARY NELSON, Primary Examiner. MILTON KAUFMAN, Examiner. 

6. A BUTTON BLEEDER VALVE COMPRISING A HOLLOW BODY, A BUTTON SLIDABLY DISPOSED WITHIN A FIRST END OF SAID BODY, SAID BUTTON HAVING A RECESS IN ITS INNER END, MEANS NORMALLY URGING SAID BUTTON TO AN EXTENDED POSITION FROM SAID FIRST END, MEANS DEFINING AN INLET CHAMBER IN A SECOND END OF SAID BODY ADAPTED FOR CONNECTION TO A PRESSURIZED AIR SOURCE, MEANS DEFINING AN EXHAUST CHAMBER IN SAID BODY INTERMEDIATE SAID FIRST AND SECOND ENDS AND A COAXIAL COMMUNICATION WITH SAID INLET CHAMBER THROUGH A PASSAGE INCLUDING A VALVE SEAT, SAID EXHAUST CHAMBER BEING PORTED TO ATMOSPHERE, A PLUNGER SLIDABLY DISPOSED WITHIN SAID RECESS OF SAID BUTTON AND DEFINING A SENSING CHAMBER THEREWITH, SAID PLUNGER PROJECTING FROM SAID RECESS COAXIALLY THROUGH SAID EXHAUST CHAMBER AND PASSAGE INTO SAID INLET CHAMBER, PASSAGE MEANS EXTENDING FROM SAID INLET CHAMBER TO SAID SENSING CHAMBER INCLUDING A PASSAGE IN SAID PLUNGER, SEAL MEANS CARRIED BY SAID PLUNGER FOR ENGAGING SAID SEAT AND BLOCKING COMMUNICATION BETWEEN SAID INLET AND EXHAUST CHAMBERS IN A FIRST POSITION OF MOVEMENT OF SAID PLUNGER TOWARDS SAID BUTTOM AND DISENGAGED FROM SAID SEAT AND ESTABLISHING COMMUNICATION BETWEEN SAID INLET AND EXHAUST CHAMBER IN A SECOND POSITION OF MOVEMENT OF SAID PLUNGER TOWARDS SAID INLET CHAMBER, MEANS NORMALLY URGING SAID PLUNGER TO SAID FIRST POSITION, AND MEANS BLOCKING COMMUNICATION THROUGH SAID PASSAGE MEANS AND EXTABLISHING COMMUNICATION BETWEEN SAID SENSING AND EXHAUST CHAMBERS WHEN SAID BUTTON IS DEPRESSED AND SAID PLUNGER IS RETURNED TO SAID FIRST POSITION. 